AUTHOPEN(1)               BSD General Commands Manual              AUTHOPEN(1)

NAME
     authopen -- open file with authorization

SYNOPSIS
     authopen [-stdoutpipe] filename
     authopen [-stdoutpipe] -w [-a] filename
     authopen [-stdoutpipe] -c [-x -m mode -w] filename
     authopen [-stdoutpipe] -o flags [-m mode] filename
     authopen -h

DESCRIPTION
     authopen provides authorization-based file opening services.  In its sim-
     plest form, authopen verifies that it is allowed to open filename (using
     an appropriate sys.openfile.* authorization right) and then writes the
     file to stdout.  If -w is specified, authopen will read from stdin and
     write to the file.

     authopen is designed to be used both from the command line and program-
     matically.  The -stdoutpipe flag allows a parent process to receive an
     open file descriptor pointing to the file in question.

     Before opening filename, authopen will make an authorization request for
     a right of the form:

     sys.openfile.[readonlyreadwritereadwritecreate]./fully/qualified/path.
     `.readonly' rights only allow for read-only file descriptors.
     `.readwrite' rights allow for read/write file descriptors.
     `.readwritecreate' rights allow for read/write descriptors and the cre-
     ation of new files.

OPTIONS
      -stdoutpipe specifies that STDOUTFILENO has been dup2()'d onto a pipe
              to a parent process and that an open file descriptor to filename
              (with the appropriate access mode) should be sent back across it
              using the SCMRIGHTS extension to sendmsg(2) rather than having
              the file itself written to or read from stdin / stdout.

      -w      instructs authopen to open filename read/write and truncate it.
              If -stdoutpipe has not been specified, authopen will then copy
              stdin to filename until stdin is closed.  -w is required for all
              of the following options:

      -a      append to filename rather than truncating it (truncating is the
              default).

      -c      create the file if it doesn't exist (-c is required for the fol-
              lowing options).

      -m mode specify the mode bits for the newly created file.

      -o flags numerically specify the flags that should be passed to open(2).

      -x      require that the file being created not exist.

EXAMPLES
     To replace /etc/hostconfig (assuming
     sys.openfile.readwrite./etc/hostconfig or better can be obtained):

           $ cat tmpdata  authopen -w /etc/hostconfig

ERORS
     authopen will fail if an appropriate sys.openfile.readonly.*,
     sys.openfile.readwrite.*, or sys.openfile.readwritecreate.* right cannot
     be obtained or if the named path does not exist.

BUGS
     authopen should should support prefix path authentication such that the
     right sys.openfile.*./dev/ could give access to all /dev entries and
     sys.openfile.*./dev/disk1 could give access to all disk1-related /dev
     entries.

     authopen should use getopt(3).

SEE ALSO
     open(2), realpath(3), recvmsg(2).

HISTORY
     authopen appeared in Mac OS X 10.1 to enable the manipulation of disk
     devices at the /dev-entry level.

Darwin                            7 May 2002                            Darwin